TWI446846B - Circuit board and manufacturing method thereof - Google Patents

Description

Circuit board and manufacturing method thereof

The present invention relates to a circuit board and a method of fabricating the same, and more particularly to a circuit board having a conductive paste through hole and a metal through hole and a method of manufacturing the same.

In recent years, with the rapid development of electronic technology, the high-tech electronics industry has come out one after another, making more humanized and better-functioning electronic products constantly innovating and designing towards light, thin, short and small trends. In these electronic products, a circuit board on which electronic components are mounted is usually disposed.

Generally, the circuit board is composed of a multi-layer circuit structure, and the circuit layers of each layer are electrically connected to each other by metal vias. When the multilayer wiring structure is formed by lamination, the interface between the metal via holes and the wiring layer may cause defects (such as cracking and incomplete bonding) due to the influence of compressive stress. In addition, these metal via holes may also be deformed by the influence of thermal stress in a high-temperature process, and thus easily cause damage to the wiring layer between the metal via holes.

The method of manufacturing a multilayer printed wiring board is disclosed in the Patent Application No. 200614898 of the Republic of China, which discloses the formation of a PET release layer on an insulating layer, the formation of via holes by laser processing, and the use of screen printing. The layer holes are filled with a conductive paste.

The invention provides a method for manufacturing a circuit board, which can manufacture a circuit board having a conductive glue through hole and a metal through hole at the same time.

The invention further provides a circuit board having a conductive adhesive through hole and a metal through hole at the same time.

The invention provides a method for manufacturing a circuit board, which first provides a line structure. The wiring structure includes a first dielectric layer, a first wiring material layer, a second wiring material layer, and a conductive paste via. The first dielectric layer has a first surface and a second surface opposite the first surface. The first line material layer is disposed on the first surface. The second line material layer is disposed on the second surface. The conductive adhesive via is disposed in the first dielectric layer and electrically connected to the first wiring material layer and the second wiring material layer. The first line of material layer is then patterned to form a first wiring layer. Next, a second dielectric layer is formed on the first surface, and the second dielectric layer covers the first wiring layer. Thereafter, a metal via hole is formed in the second dielectric layer, and a third circuit material layer is formed on the second dielectric layer, wherein the metal via hole is connected to the first circuit layer and the third circuit material layer, and the metal via hole Electrically connected to the first circuit layer and the third circuit material layer.

The invention further provides a method of manufacturing a circuit board, which first provides a line structure. The wiring structure includes a first dielectric layer, a first wiring material layer, a second wiring material layer, and a metal via. The first dielectric layer has a first surface and a second surface opposite the first surface. The first line material layer is disposed on the first surface. The second line material layer is disposed on the second surface. The metal via is disposed in the first dielectric layer and electrically connected to the first circuit material layer and the second circuit material layer. Then, patterning the first line material layer, To form a first circuit layer. Next, a second dielectric layer is formed on the first surface, and the second dielectric layer covers the first wiring layer. Then, a first via hole is formed in the second dielectric layer, and the first via hole exposes a portion of the first wiring layer. Then, a conductive rubber via hole is formed in the first via hole. Thereafter, a third line material layer is formed on the second dielectric layer and the conductive paste via.

The invention further provides a circuit board comprising a first line structure and a second line structure. The first line structure includes a first dielectric layer, a first circuit layer, a second circuit layer, and a metal via. The first dielectric layer has a first surface and a second surface opposite the first surface. The first circuit layer is disposed on the first surface. The second circuit layer is disposed on the second surface. The metal vias are disposed in the first dielectric layer and electrically connected to the first circuit layer and the second circuit layer, wherein the metal vias connect the first circuit layer and the second circuit layer. The second line structure is disposed on the first surface. The second line structure includes a third circuit layer, a second dielectric layer, and a conductive paste via. The third circuit layer is disposed on the first circuit layer. The second dielectric layer is disposed between the first circuit layer and the third circuit layer. The conductive adhesive via is disposed in the second dielectric layer and electrically connected to the first circuit layer and the third circuit layer.

Based on the above, since the circuit board of the present invention has oppositely disposed conductive rubber vias and metal vias, when the circuit board is subjected to a subsequent pressing process to form a circuit board having a more layer wiring structure, the conductive adhesive is turned on. The hole can serve as a buffer structure, so that the interface between the metal via hole and the wiring layer can be prevented from being defective due to the influence of compressive stress (such as cracking and incomplete bonding).

In addition, in the circuit board of the present invention, the conductive via hole can be As the buffer structure, when the metal via hole is deformed due to the process temperature being too high, the metal via hole can be effectively prevented from being pressed against the circuit layer to cause damage to the circuit layer.

The above described features and advantages of the present invention will be more apparent from the following description.

1A-1E are cross-sectional views showing a method of fabricating a circuit board according to an embodiment of the invention. First, referring to FIG. 1A, a first dielectric layer 101 is provided. The first dielectric layer 101 has a first surface 101a and a second surface 101b opposite the first surface 101a. Then, a first wiring material layer 102 is formed on the first surface 101a. The first line material layer 102 is, for example, a copper layer. The step of forming the first line material layer 102 is, for example, an electroplating process. Thereafter, an insulating film 103 is formed on the second surface 101b. The material of the insulating film 103 is, for example, polyethylene terephthalate (PET). The step of forming the insulating film 103 is, for example, a press-bonding process. However, in another embodiment, the first circuit material layer 102 and the insulating film 103 may also be formed on the first surface 101a and the second surface 101b by press-bonding, respectively.

Then, referring to FIG. 1B, a via hole 104 is formed in the insulating film 103 and the first dielectric layer 101, and the via hole 104 exposes a portion of the first circuit material layer 102. The step of forming the via 104 is, for example, a laser drilling process. Next, a conductive paste via 105 is formed in the via 104. The step of forming the conductive paste via 105 is, for example, a printing process to transfer a conductive paste (such as silver) Glue, copper glue, etc.) are filled into the through holes 104.

Next, referring to FIG. 1C, the insulating film 103 is removed. Then, a second circuit material layer 106 is formed on the second surface 101b and the conductive paste via 105 to form the wiring structure 100. The second line material layer 106 is, for example, a copper layer. The step of forming the second line material layer 106 is, for example, a embossing process. The conductive paste vias 105 electrically connect the first line material layer 102 and the second line material layer 106. In particular, in the press-bonding process, since the conductive adhesive has not been hardened, the conductive adhesive via 105 outside the through hole 104 is simultaneously pressed into the through hole 104, and is formed by flattening after high temperature and high pressure. Pressing the surface. At this time, the conductive paste via 105 has a top portion 105a and a bottom portion 105b, the bottom portion 105b is adjacent to the first surface 101a, and the top portion 105a is adjacent to the second surface 101b, and the outer diameter of the top portion 105a is larger than the outer diameter of the bottom portion 105b. In the present embodiment, the bottom portion 105b is flush with the first surface 101a, and the top portion 105a is flush with the second surface 101b.

Then, referring to FIG. 1D, the first circuit material layer 102 and the second wiring material layer 106 in the circuit structure 100 are patterned to form a first wiring layer 102a and a second wiring layer 106a, respectively. In another embodiment, it is also possible to pattern only the first line material layer 102, and then pattern the second line material layer 106 in subsequent steps, depending on actual needs. Then, a second dielectric layer 111 is formed on the first surface 101a, and the second dielectric layer 111 covers the first wiring layer 102a. Next, a metal via hole 113 is formed in the second dielectric layer 111, and a third wiring material layer 114 is formed on the second dielectric layer 111. The metal via hole 113 is connected to the first wiring layer 102a and the third wiring layer 114, and the metal via hole 113 and the first wiring layer 102a and the The three circuit layers 114 are electrically connected. The step of forming the metal vias 113 and the third wiring material layer 114 is, for example, forming the vias 112 in the second dielectric layer 111. The step of forming the through holes 112 is, for example, performing laser drilling. The through hole 112 exposes a portion of the first wiring layer 102a. Thereafter, an electroplating process is performed to form a metal via hole 113 in the via hole 112 and a third wiring material layer 114 on the second dielectric layer 111. The metal via 113 has a top portion 113a adjacent to the first surface 101a and a top portion 113a away from the first surface 101a, and the outer diameter of the top portion 113a is larger than the outer diameter of the bottom portion 113b.

Thereafter, referring to FIG. 1E, the third wiring material layer 114 is patterned to form a third circuit layer 114a to complete the fabrication of the wiring board 10 of the present embodiment.

2A-2E are cross-sectional views showing a method of fabricating a circuit board according to another embodiment of the present invention. In the present embodiment, the formed wiring board has the same structure as the wiring board 10. First, referring to FIG. 2A, a first dielectric layer 201 is provided. The first dielectric layer 201 has a first surface 201a and a second surface 201b opposite the first surface 201a. Then, a first wiring material layer 202 is formed on the first surface 201a. The first line material layer 202 is, for example, a copper layer. The step of forming the first line material layer 202 is, for example, an electroplating process.

Then, referring to FIG. 2B, a metal via hole 204 is formed in the first dielectric layer 201, and a second circuit material layer 205 is formed on the second surface 201b to form the wiring structure 200. The step of forming the metal via 204 and the second wiring material layer 205 is, for example, forming a pass before the first dielectric layer 201. Hole 203. The step of forming the through holes 203 is, for example, performing laser drilling. The via 203 exposes a portion of the first line material layer 202. Thereafter, an electroplating process is performed to form a metal via hole 204 in the via hole 203 and a second wiring material layer 205 on the first dielectric layer 201. The metal vias 204 are electrically connected to the first wiring material layer 202 and the second wiring material layer 205. The metal via 204 has a top 204a and a bottom 204b, the bottom 204b is adjacent to the first surface 201a, and the top 204a is adjacent to the second surface 201b, and the outer diameter of the top 204a is greater than the outer diameter of the bottom 204b. In the present embodiment, the bottom portion 204b is flush with the first surface 201a, and the top portion 204a is flush with the second surface 201b.

Next, referring to FIG. 2C, the first line material layer 202 in the line structure 200 is patterned to form a first circuit layer 202a. In another embodiment, the first line material layer 202 and the second line material layer 205 may also be patterned simultaneously according to actual needs. Then, a second dielectric layer 211 is formed on the first surface 201a, and the second dielectric layer 211 covers the first wiring layer 202a. Then, an insulating film 212 is selectively formed on the second dielectric layer 211. The material of the insulating film 212 is, for example, polyethylene terephthalate (PET). The step of forming the insulating film 212 is, for example, a press-bonding process.

Then, referring to FIG. 2D, a through hole 213 is formed in the insulating film 212 and the second dielectric layer 211, and the through hole 213 exposes a portion of the first wiring layer 202a. The step of forming the through holes 213 is, for example, a laser drilling process. Next, a conductive paste via 214 is formed in the via hole 213. The step of forming the conductive paste via 214 is, for example, a printing process to fill a conductive paste (such as silver paste, copper paste, etc.) into the through hole 213.

Thereafter, referring to FIG. 2E, the insulating film 212 is removed. Then, in the first A third circuit material layer (not shown) is formed on the second dielectric layer 211 and the conductive paste vias 214. The third line material layer is, for example, a copper layer. The step of forming the third line material layer is, for example, a press-bonding process. The conductive paste via 214 electrically connects the first circuit layer 202a and the third circuit layer 215. In particular, in the press-bonding process, the conductive adhesive vias 214 outside the vias 213 are simultaneously pressed into the vias 213. The conductive adhesive via 214 has a top portion 214a adjacent to the first surface 201a and a bottom portion 214b away from the first surface 201a, and the outer diameter of the top portion 214a is greater than the outer diameter of the bottom portion 214b.

Thereafter, the third wiring material layer is patterned to form a third wiring layer 215 to complete the manufacture of the wiring board 20 of the present embodiment.

As shown in FIG. 1E and FIG. 2E, the circuit boards 10 and 20 have opposite conductive conductive vias and metal vias, so that the circuit boards 10 and 20 are subjected to a subsequent pressing process to form a plurality of layers. When the circuit board of the structure is used, the conductive adhesive vias 105, 214 can serve as a buffer structure, thereby avoiding the influence of compressive stress and causing defects in the interface between the metal vias 113, 204 and the first circuit layers 102a, 202a (eg, The problem of cracking and incomplete bonding.

In addition, in the circuit boards 10 and 20, since the conductive vias 105 and 214 can serve as a buffer structure, when the metal vias 113 and 204 are deformed due to excessive process temperature, the metal vias 113 can be effectively avoided. The pressing of the first wiring layers 102a, 202a causes the first wiring layers 102a, 202a to be damaged.

For subsequent embossing processes to form more layers of line junctions The circuit board of the structure will be described below by taking the circuit board 10 as an example.

3A-3B are cross-sectional views showing a method of fabricating a circuit board according to still another embodiment of the present invention. First, referring to Fig. 3A, wiring boards 10, 10' are provided. The wiring board 10 has the same structure as the wiring board 10'. Then, a dielectric layer 300 is provided between the wiring board 10 and the wiring board 10', and a dielectric layer 302 and a wiring material layer 304 are provided on a side of the conductive adhesive via 105 adjacent to the wiring board 10. Further, a dielectric layer 306 and a wiring material layer 308 are provided on one side of the conductive paste via 105 adjacent to the wiring board 10', and a tapered conductive paste 30 is formed on the third circuit layer 114a of the wiring board 10'.

Then, referring to FIG. 3B, the line material layer 304, the dielectric layer 302, the wiring board 10, the dielectric layer 300, the wiring board 10', the dielectric layer 306, and the wiring material layer 308 are laminated. During the pressing process, the tapered conductive paste 30 passes through the dielectric layer 300 to form a conductive adhesive via 30a. Next, a via hole is formed in the wiring material layer 304 and the dielectric layer 302 and an electroplating process is performed to form the metal via hole 312 and the build-up wiring material layer 314, and a via hole is formed in the wiring material layer 308 and the dielectric layer 306. An electroplating process is performed to form metal vias 316 and build-up wiring material layers 318. Thereafter, the wiring material layers 314, 304 can be patterned and the wiring material layers 318, 308 patterned to form the desired wiring layer.

4A-4B are cross-sectional views showing a method of fabricating a circuit board according to still another embodiment of the present invention. First, referring to Fig. 4A, wiring boards 10, 10' are provided. The wiring board 10 has the same structure as the wiring board 10'. Then, a dielectric layer 400, a metal via 402 and a wiring layer 404 are formed on the wiring board 10, and a dielectric layer 410 and a metal via hole are formed on the wiring board 10'. 412, the circuit layer 414 and the tapered conductive paste 40. Next, a dielectric layer 406 and a wiring material layer 408 are provided on one side of the wiring board 10, and a dielectric layer 409 is provided between the wiring boards 10, 10'. Further, a dielectric layer 416 and a wiring material layer 418 are provided on a side of the wiring board 10' opposite to the tapered conductive paste 40.

Then, referring to FIG. 4B, the wiring material layer 408, the dielectric layer 406, the wiring board 10, the dielectric layer 409, the wiring board 10', the dielectric layer 416, and the wiring material layer 418 are laminated. During the pressing process, the tapered conductive paste 40 passes through the dielectric layer 409 to form a conductive adhesive via 40a. Next, a via hole is formed in the wiring material layer 408 and the dielectric layer 406 and an electroplating process is performed to form the metal via hole 420 and the wiring material layer 422, and a via hole is formed in the wiring material layer 418 and the dielectric layer 416 and is plated. The process is to form metal vias 424 and trace material layer 426. Thereafter, the wiring material layers 422, 408 can be patterned and the wiring material layers 426, 418 patterned to form the desired wiring layer.

In summary, since the circuit board of the present invention has oppositely disposed conductive rubber vias and metal vias, when the circuit board is subjected to a subsequent pressing process to form a circuit board having a more layer wiring structure, the conductive layer is electrically conductive. The through hole can be used as a buffer structure, so that the interface between the metal via and the circuit layer can be prevented from being defective due to the influence of compressive stress (such as cracking and incomplete bonding).

In addition, in the circuit board of the present invention, since the conductive paste via hole can serve as a buffer structure, when the metal via hole is deformed due to excessive process temperature, the metal via hole can be effectively prevented from being pressed to the circuit layer to cause the circuit layer. Damage occurred.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the invention, and any one of ordinary skill in the art can make some modifications and refinements without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

10, 20, 10’‧‧‧ boards

30, 40‧‧‧Conical conductive adhesive

100, 200‧‧‧ line structure

101, 201‧‧‧ first dielectric layer

101a, 201a‧‧‧ first surface

101b, 201b‧‧‧ second surface

102, 202‧‧‧First line material layer

102a, 202a‧‧‧ first line layer

103, 212‧‧‧Insulation film

104, 112, 203, 213‧‧‧ through holes

105, 214, 30a, 40a‧‧‧ conductive rubber vias

105a, 113a, 204a, 214a‧‧‧ top

105b, 113b, 204b, 214b‧‧‧ bottom

106, 205‧‧‧ second line material layer

106a‧‧‧Second circuit layer

111‧‧‧Second dielectric layer

113, 204, 312, 316, 402, 412, 420, 424‧‧‧ metal vias

114‧‧‧ Third line material layer

114a‧‧‧ third circuit layer

215‧‧‧ third circuit layer

302, 306, 400, 406, 409, 410, 416‧‧ dielectric layers

304, 308, 314, 318, 408, 418, 422, 426‧‧‧ line material layer

404, 414‧‧‧ circuit layer

1A-1E are cross-sectional views showing a method of fabricating a circuit board according to an embodiment of the invention.

2A-2E are cross-sectional views showing a method of fabricating a circuit board according to another embodiment of the present invention.

3A-3B are cross-sectional views showing a method of fabricating a circuit board according to still another embodiment of the present invention.

4A-4B are cross-sectional views showing a method of fabricating a circuit board according to still another embodiment of the present invention.

10‧‧‧ circuit board

101‧‧‧First dielectric layer

102a‧‧‧First circuit layer

105‧‧‧conductive rubber vias

106a‧‧‧Second circuit layer

111‧‧‧Second dielectric layer

113‧‧‧Metal vias

114a‧‧‧ third circuit layer

Claims (11)

A method of manufacturing a circuit board, comprising: providing a circuit structure, the circuit structure comprising: a first dielectric layer having a first surface and a second surface opposite to the first surface; a first circuit material layer And disposed on the first surface; a second circuit material layer disposed on the second surface; and a conductive adhesive via disposed in the first dielectric layer and electrically connected to the first circuit material a layer and the second circuit material layer; patterning the first circuit material layer to form a first circuit layer; forming a second dielectric layer on the first surface, the second dielectric layer covering the first layer a circuit layer; a metal via hole is formed in the second dielectric layer, and a third circuit material layer is formed on the second dielectric layer, wherein the metal via hole and the first circuit layer and the first The three-line material layers are connected, and the conductive rubber vias and the metal vias are aligned with each other. The method of manufacturing a circuit board according to claim 1, wherein the conductive adhesive via has a top portion and a bottom portion, the bottom portion is adjacent to the first surface, and the top portion is adjacent to the second surface, and the top portion is The outer diameter is larger than the outer diameter of the bottom. The method of manufacturing a circuit board according to claim 1, wherein the metal via has a top portion and a bottom portion, the bottom portion is adjacent to the first surface, and the top portion is away from the first surface, and the top portion is outside The diameter is larger than the outer diameter of the bottom. The method of manufacturing the circuit board of claim 1, wherein the step of forming the circuit structure comprises: providing the first dielectric layer; forming the first circuit material layer on the first surface; Forming an insulating film on the surface; forming a through hole in the insulating film and the first dielectric layer, the through hole exposing a portion of the first circuit material layer; forming the conductive glue via hole in the through hole; And forming the second circuit material layer on the second surface and the conductive paste via. A method of manufacturing a circuit board, comprising: providing a circuit structure, the circuit structure comprising: a first dielectric layer having a first surface and a second surface opposite to the first surface; a first circuit material layer And disposed on the first surface; a second circuit material layer disposed on the second surface; and a metal via hole disposed in the first dielectric layer and electrically connected to the first circuit material layer And the second circuit material layer; patterning the first circuit material layer to form a first circuit layer; forming a second dielectric layer on the first surface, the second dielectric layer covering the first a circuit layer; a first via hole is formed in the second dielectric layer, the first via hole exposing a portion of the first circuit layer; Forming a conductive adhesive via in the first via, and the conductive via is aligned with the metal via; and forming a third trace material on the second dielectric layer and the conductive via. Floor. The method of manufacturing a circuit board according to claim 5, wherein the metal via has a top portion and a bottom portion, the bottom portion is adjacent to the first surface, and the top portion is adjacent to the second surface, and the top portion is outside The diameter is larger than the outer diameter of the bottom. The method of manufacturing a circuit board according to claim 5, wherein the conductive adhesive via has a top portion and a bottom portion, the bottom portion is adjacent to the first surface, and the top portion is away from the first surface, and the top portion is The outer diameter is larger than the outer diameter of the bottom. The method of manufacturing a circuit board according to claim 5, wherein the step of forming the circuit structure comprises: providing the first dielectric layer; forming the first circuit material layer on the first surface; The metal via hole is formed in the first dielectric layer, and the second circuit material layer is formed on the second surface. A circuit board comprising: a first circuit structure comprising: a first dielectric layer having a first surface and a second surface opposite the first surface; a first circuit layer disposed on the first a second circuit layer disposed on the second surface; a metal via hole disposed in the first dielectric layer and connecting the first circuit layer and the second circuit layer; and a second circuit structure disposed on the first surface, the second circuit structure including a second dielectric layer is disposed on the first surface and covers the first circuit layer; a third circuit layer is disposed on the second dielectric layer; and a conductive adhesive via is disposed in the The second dielectric layer is electrically connected to the first circuit layer and the third circuit layer, and the conductive rubber vias and the metal vias are aligned with each other. The circuit board of claim 9, wherein the metal via has a top and a bottom, the bottom is adjacent to the first surface, and the top is adjacent to the second surface, and an outer diameter of the top is larger than the The outer diameter of the bottom. The circuit board of claim 9, wherein the conductive adhesive via has a top portion and a bottom portion, the bottom portion is adjacent to the first surface, and the top portion is away from the first surface, and an outer diameter of the top portion is larger than The outer diameter of the bottom.